Clinical Significance of Serum Soluble Interleukin-6 Receptor Level in Multiple Myeloma

Abstract

Objective To study the relationship between serum soluble interleukin 6 receptor (sIL-6R) and treatment efficacy and prognosis of multiple myeloma (MM),and explore its clinical significance of sIL-6R.Methods Form July 2006 to December 2011,67 MM patients who received treatment in Beijing Chaoyang hospital,Capital Medical University were selected into this study.According to age of patents,they were divided into the older group (＞65 years old,n=20) and young group (≤65 years old,n=47).According to Durie-Salmon (DS) staging criteria,the patients were divided into DS Ⅰ/Ⅱ stage group (n=8) and Ⅲ stage group (n=59).According to the International Staging system (ISS) criteria,the patients were divided into ISS Ⅰ stage group (n 6),stage Ⅱ stage group (n 19) and Ⅲ stage group (n=42).According to the immune classification criteria,the patients were divided into IgA group (n=19),IgG group (n=23),light chain group (n=19) and other types group (n 6).According to the median serum sIL-6R levels of patients,they were divided into sIL-6R≤500 ng/ L group (n 43) and ＞500 ng/L group (n 24).After four to six courses of treatment,there were 29 cases of MM patients could evaluate the efficacy.According to the efficacy of patients,they were divided into ≥partial remission (PR) group (n 25)and ＜PR group (n=4).(The study protocol was approved by the Ethical Review Board of Investigation in Human Being of Beijing Chaoyang hospital.Informed consent was obtained from all participants.) The serum levels of sIL-6R were detected by enzyme-linked immunosorbent assay technique in 67 patients with MM.The serum sIL-6R levels of MM patients in different ages,immunophenotypes and clinical stages were compared.The relationship between serum levels of sIL-6R between patient outcomes and survival were analyzed.Results sIL-6R levels of MM patients in older group were (496.6±204.4) ng/L,which were similar with the young group[(494.8±260.0) ng/L)] (t=0.027,P=0.98).Patients in IgA type group had lower sIL-6R levels [(418.0±137.1) ng/L] than those of IgG type group [(590.6±285.5) ng/L] and light chain type group [(475.6±253.0) ng/L],but there were no statistical significance among these three groups (F=2.895,P＞0.05).Patients with DS stage Ⅰ/Ⅱ had higher sIL-6R levels [(598.1± 347.2) ng/L] than those of stage Ⅲ [(482.3±226.5) ng/L],and it also had no statistical significance (t=1.199,P＞0.05).Patients with ISS stage Ⅰ had lower sIL-6R levels [(469.5±271.4) ng/L] than those of stage Ⅱ [(510.9±239.9) ng/L] and stage Ⅲ [(492.1 ± 146.4) ng/L],and it also had no statistical significance (F 0.074,P＞0.05).After treatment,patients who obtained PR or more had decrease of sIL-6R levels (t=1.759,P=0.08),patients who obtained less than PR had increase of sIL-6R levels (t =0.285,P=0.78).Patients with sIL-6R ≤500 ng/L had longer overall survival time than those of ＞ 500 ng/L (32.3 months vs.19.6 months),however their had no statistical significance (P=0.18).Conclusions Serum sIL-6R levels of MM patients had no association with age,clinical stages and immunophenotype.There maybe a certain relationship among sIL 6R levels of MM patients,efficacy and survival prognosis. Key words: Multiple myeloma; Receptor,interleukin-6; Prognosis